|
Backfire on Deceleration
So I finally put my webers back on the car. Bear in mind I put in a new cam recommended by Keith Craft so I had my 4 barrel on there to reduce the variables until I was sure I did that right.. :LOL:
Now that the webers are on there it did mellow the cam out a little bit boy is it meaner now with the throttle.. **) I spun the tires a few times without even intending to. It seems to run really well from idle up to almost WOT. I don't want to get on it too hard yet since the cam has only been in the motor for about 400 miles. Ill give it another 100 first. However on decel if I leave the clutch out and pull off the throttle, sometimes I get a mild backfire. Could this be I am too lean or air getting into the exhaust? It only happens on the right side. |
air into the exhaust, look for a leak.
|
What are you cam specs?
|
Just curious ,,but why are you concerned about going easy on it for another 100 miles? Its either broke in or not and that is done in the first 15 min or so of run time. ?
|
Quote:
http://www.clubcobra.com/photopost/d.../SCAN00013.jpg |
Quote:
|
try tightening headder, possible bad gasket
|
Cam looks good.
What kind of webers, 48ida or idf and what venturi size and jetting. |
Quote:
Main Venturi: 37 Aux Venturi: 4.5 Main Jet: 155 Emulsion Tube: F16 Air Corrector: 175 Idle Jet: 65F10 Idle Jet Holder: 120 Pump Jet: 50 Exhaust Valve: 000 Needle and Seat: 2.00 |
Looks good.
I would recomend changing your venturi size to say 38 or as high as 40. But for now re-check your syncronization using a syncrometer with engine hot. And get your self an air /fuel ratio meter. Very helpful with webers. PS. remember that if you change venturi size that can affect making changes to jetting sizes and air correctors on idle circuit and main circuit. |
Yep.. that was it.. I tore apart the left side exhaust and re-did all the gaskets.. No more backfire.. Car runs great. I punched it a couple of times on a back road and quickly remembered "Respect the Cobra" :)
|
Good call Ray Humbel.
|
| All times are GMT -7. The time now is 04:58 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: